Uplink coordinated multi-point

ABSTRACT

Disclosed embodiments may include an apparatus having one or more processors coupled to one or more computer-readable storage media. The one or more processors may be configured to transmit and/or receive channel state information reference signal (CSI-RS) resource configuration information, demodulation reference signals (DM-RS), uplink sounding reference signals (SRS), and power control parameters to support uplink coordinated multi-point (CoMP) operations. Other embodiments may be disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. patent application Ser.No. 13/536,722, filed Jun. 28, 2012, entitled “UPLINK COORDINATEDMULTI-POINT,” which claims priority to U.S. Provisional PatentApplication No. 61/591,641, filed Jan. 27, 2012, entitled “ADVANCEDWIRELESS COMMUNICATION SYSTEMS AND TECHNIQUES,” the entire disclosuresof which are hereby incorporated by reference.

FIELD

Embodiments of the present invention relate generally to the field ofcommunications, and more particularly, to uplink coordinated multi-pointoperation in wireless communication networks.

BACKGROUND INFORMATION

Coordinated multi-point (CoMP) is an interference avoidance concept thatcan be used to improve system spectral efficiency and cell edge userthroughput performance. CoMP may be used to avoid interference to othercells by coordination of the transmissions across multiple eNBs.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example, and notby way of limitation, in the figures of the accompanying drawings inwhich like reference numerals refer to similar elements.

FIG. 1 schematically illustrates a wireless communication network inaccordance with various embodiments.

FIG. 2 illustrates a flow diagram of signaling UE-specific SRSparameters in accordance with various embodiments.

FIG. 3 illustrates a flow diagram of physical uplink control channel(PUCCH) resource allocation and PUCCH sequence assignment for efficientsupport of UL CoMP in accordance with various embodiments.

FIG. 4 illustrates a flow diagram of signaling UE-specific UL DM-RSparameters in accordance with various embodiments.

FIG. 5 schematically depicts an example system in accordance withvarious embodiments.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present disclosure may relate to uplink (UL)coordinated multi-point (CoMP) in wireless communication networks. Inparticular, embodiments of the present disclosure may relate to definingaspects of a control and signaling framework for operation of UL CoMP.

Various aspects of the illustrative embodiments will be described usingterms commonly employed by those skilled in the art to convey thesubstance of their work to others skilled in the art. It will beapparent to those skilled in the art, however, that some alternateembodiments may be practiced using portions of the described aspects.For purposes of explanation, specific numbers, materials, andconfigurations are set forth in order to provide a thoroughunderstanding of the illustrative embodiments. It will be apparent toone skilled in the art, however, that alternate embodiments may bepracticed without the specific details. In other instances, well-knownfeatures are omitted or simplified in order to not obscure theillustrative embodiments.

Further, various operations will be described as multiple discreteoperations, in turn, in a manner that is most helpful in understandingthe illustrative embodiments; however, the order of description shouldnot be construed as to imply that these operations are necessarily orderdependent. In particular, these operations need not be performed in theorder of presentation.

The phrase “in one embodiment” is used repeatedly. The phrase generallydoes not refer to the same embodiment; however, it may. The terms“comprising,” “having,” and “including” are synonymous, unless thecontext dictates otherwise. The phrase “A/B” means “A or B”. The phrase“A and/or B” means “(A), (B), or (A and B)”. The phrase “at least one ofA, B and C” means “(A), (B), (C), (A and B), (A and C), (B and C) or (A,B and C)”. The phrase “(A) B” means “(B) or (A B)”, that is, A isoptional.

As used herein, the term “module” may refer to, be part of, or includean Application Specific Integrated Circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group) and/or memory(shared, dedicated, or group) that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablecomponents that provide the described functionality.

FIG. 1 schematically illustrates a wireless communication network 100 inaccordance with various embodiments. Wireless communication network 100(hereinafter “network 100”) may be an access network of a 3rd GenerationPartnership Project (3GPP) long-term evolution (LTE) network such asevolved universal mobile telecommunication system (UMTS) terrestrialradio access network (E-UTRAN). Network 100 may be configured to supportuplink (UL) coordinated multipoint (CoMP) operation, for which there ispresently no specification defined by the 3GPP standards body. The ULCoMP operations may include determining a UL CoMP cooperating set thatmay be a set of points intended to receive data from a UE. The UL CoMPcooperating set may be UE-specific and, if signaled to the UE, may beset or changed dynamically via radio resource control (RRC) or mediumaccess control (MAC) signaling. The network 100 may include a mobiledevice or terminal, e.g., user equipment (UE) 104, configured towirelessly communicate with a number of base stations, e.g., enhancednode base stations (eNB) 108 a, 108 b, and 108 c (collectively 108).While embodiments of the present invention are described with referenceto an LTE network, some embodiments may be used with other types ofwireless access networks.

UE 104 and eNBs 108 may be configured to determine, provide, and/orreceive control signaling and message signaling parameters to support ULCoMP operations in network 100. The control and message signalingparameters may include channel state information reference signals(CSI-RS) resource configuration parameters, open loop power controlparameters, UL demodulation reference signals (DM-RS) parameters,sounding reference signal (SRS) parameters, and parameters related tophysical uplink control channel (PUCCH) resource allocation. Theconfigurations of UE 104 and eNBs 108 to enable determining, providing,and/or receiving of the parameters will be discussed below one parameterat a time.

UE 104 may include a communications module 112 coupled to one or moreantennas 116. Communications module 112 may include physical layercircuitry 118 coupled to one or more antennas 116, MAC layer circuitry120, user plane circuitry 122, control plane circuitry 124, and RRCcircuitry 126. As shown, control plane circuitry 124 and user planecircuitry 122 may be communicatively coupled to physical layer circuitry118 through MAC layer circuitry 120. In other words, MAC layer circuitry120 may be an interface configured to communicate user plane signalsand/or control plane signals to and/or from physical layer circuitry118. Additionally, RRC circuitry 126 may be integrated into controlplane circuitry 124.

eNBs 108 may collectively be configured as a UL CoMP cooperating set,and one or more eNBs 108 may be configured as an UL CoMP reception point(RP) set with respect to UE 104, according to various embodiments. A ULCoMP RP set may be a set of points that a may actively receive data fromUE 104. The UL CoMP RP set may be a subset of a UL CoMP cooperating set.eNB 108 a, may include a communications module 128, and one or moreantennas 130. Communications module 128 may include physical layercircuitry 132, MAC layer circuitry 134, user plane circuitry 138, andcontrol plane circuitry 138. Additionally, MAC layer circuitry 134 mayinclude MAC control element (MAC-CE) circuitry 142, and control planecircuitry 140 may include RRC circuitry 144. Control plane circuitry 132and user plane circuitry 138 may be communicatively coupled to physicallayer circuitry 132 through MAC layer circuitry 134. In other words, MAClayer circuitry 134 may be an interface configured to communicate userplane signals and/or control plane signals to and/or from physical layercircuitry 132.

eNBs 108 b and 108 c may include similar features as eNB 108 a todetermine, provide, and/or receive control signaling and messagesignaling parameters to support UL CoMP operations in network 100.

CSI-RS resource configuration may include information on transmit power,periodicity, subframe offset, initialization seeds, and number ofantenna ports available on UE 104 and/or eNBs 108. According to oneembodiment, CSI-RS may include information to enable UE 104 to identifyand select a particular point, e.g., reception point. eNB 108 a mayprovide the CSI-RS resource configuration through the CoMPinitialization process via control signaling. For example, eNB 108 a mayprovide the CSI-RS resource configuration with RRC circuitry 144 throughRRC signaling.

eNB 108 a may be configured to assign an index to each CSI-RS resourcein a CoMP Resource Management (CRM) set, when defined. The CRM set maybe a set of CSI-RS resources for which CSI-RS based received signalmeasurements can be made and reported. eNB 108 a may alternatively beconfigured to assign an index to each CSI-RS resource in a set of pointsthat measure UE 104 UL transmissions for pathloss estimations. eNB 108 amay assign the indices implicitly, based on the order of CSI-RSsincluded in a CSI-RS configuration message, or eNB 108 may assign a 3-4bit index to each CSI-RS resource. According to embodiments, CSI-RSresource indices may be assigned as part of RRC configuration orinitialization.

Alternatively, eNB 108 a may assign an index to each CSI-RS resourcebased on an order of CSI-RSs included in a CSI-RS configuration message.

eNB 108 a may be configured to reuse CSI-RS resource configuration ofdownlink CoMP. For example, eNB 108 a may be configured to reuse theCSI-RS resource configuration of DL CoMP to facilitate the signaling andconfiguration information that supports UL CoMP. Alternatively, eNB 108a may independently incorporate the reused CSI-RS configuration duringUL CoMP initiation. Further, eNB 108 a may use the CSI-RS resourceconfiguration to identify and signal additional UL parameters, asdescribed below.

UE 104 and/or eNB 108 a may be configured to identify each point in theUL CoMP cooperating set using the respective CSI-RS resource index ofthe point. Accordingly, respective CSI-RS resource indices may be usedas a pointer to a particular CSI-RS resource during subsequentsignaling. If eNB 108 a assigns CSI-RS resource indices during RRCconfiguration, eNB 108 may explicitly or implicitly define the indicesbased on the order of CSI-RSs present in the corresponding RRC message.eNB 108 may similarly assign CSI-RS indices for DL and UL operations.However, the UL CoMP cooperating set, may be different from the DL CoMPCSI measurement set, according to various embodiments.

UE 104 and/or eNB 108 may be configured to select, determine, or updateUL power control (PC) parameters based on a removal or addition of an RPto a CoMP RP set. An example of the UL PC parameter set may be definedTABLE 1, according to one embodiment.

TABLE 1 ULCoMPConfigDedicated ::=    SEQUENCE { csi-rs-ConfigList    CSI-RS-ConfigList, p0-NominalPUSCH-ULCoMP INTEGER (−126..24),p0-NominalPUCCH-ULCoMP INTEGER (−127..−96), deltaFList-PUCCH-DedicatedDeltaFList-PUCCH-Dedicated } DeltaFList-PUCCH-Dedicated ::= SEQUENCE {deltaF-PUCCH-Format1 ENUMERATED {deltaF-2, deltaF0, deltaF2},deltaF-PUCCH-Format1b ENUMERATED {deltaF1, deltaF3, deltaF5},deltaF-PUCCH-Format2 ENUMERATED {deltaF-2, deltaF0, deltaF1, deltaF2},deltaF-PUCCH-Format2a ENUMERATED {deltaF-2, deltaF0, deltaF2},deltaF-PUCCH-Format2b ENUMERATED {deltaF-2, deltaF0, deltaF2},deltaF-PUCCH-Format3-r10 ENUMERATED {deltaF-1, deltaF0, deltaF1,deltaF2, deltaF3, deltaF4, deltaF5, deltaF6},      deltaF-PUCCH-Format1bCS-r10 ENUMERATED

Each time an RP is added or removed/replaced in a CoMP RP set, UE 104and/or eNB 108 a may update or redefine the UL PC parameters, accordingto various embodiments of the disclosure.

According to a first embodiment, eNB 108 a may set or determine thepower control parameters in a dynamic RRC message, MAC message, orphysical layer (PHY) message. According to embodiments, eNB 108 a mayset UL PC parameter and indicate the CoMP RP set in the same RRC, MAC,or PHY message. Setting the PC parameter in the same RRC, MAC, or PHYmessage as indicating the CoMP RP set may provide more flexibility thanother techniques used to set PC parameters.

Control plane circuitry 124 of UE 104 may be configured to receive theRRC, MAC, or PHY message, and determine UL PC parameters for UE 104based on the message.

UL PC parameters may be cell specific and semi-static. Therefore,according to a second embodiment, eNB 108 a may be configured togenerate a list or set of UL PC parameter sets applicable to differentcombinations of RPs. eNB 108 a may generate the list or set of UL PCparameter sets based on the CSI-RS resource indices of the points. RRCcircuitry 126 of UE 104 may then receive the list or set of UL PCparameter sets via RRC messaging. The list or set of UL PC parametersets may be subsequently updated by MAC signaling, e.g., between MAClayer circuitry 134 to MAC layer circuitry 120 or between MAC-CEcircuitry 142 to MAC circuitry 120. Through MAC layer dynamic signalingof the CoMP RP set, control plane circuitry 124 of UE 104 may apply theupdated UL PC parameters.

If a small number of RP sets are allowed for joint reception or ifcoordinated scheduling and beamforming (CS/CB) base UL CoMP is used,generating lists or sets of UL PC parameter sets by eNB 108 a may bemore efficient than setting UL PC parameters in the same dynamic messageused to indicate the CoMP RP set.

Advantageously, referencing the UL PC parameters with CSI-RS resourceindices of the points in the CoMP RP set may enable UE 104 to determinepathloss information using average received power measured by UE 104 onCSI-RS. Based on the optimality-signaling overhead tradeoff, it may besufficient to semi-statically signal the CSI-RS resource index of onlythe preferred RP via RRC layer, especially in low-mobility scenarios. Inembodiments, low-mobility scenarios include speeds that areapproximately 3 km/h and less.

If eNB 108 a configures the UL PC parameters and pathloss offset valuesin a UE-specific manner, control plane circuitry 124 of UE 104 maydirectly receive UL PC parameters and pathloss offset values by thesignaling of the appropriate indices in the list(s) of UL PC parametersand pathloss offset values via RRC, MAC, or PHY messaging by the eNB 108a.

The parameters for UL DM-RS include parameters that may enable UE 104 tochoose a base sequence, cyclic shift (CS), and orthogonal cover code(OCC) for a DM-RS sequence for the UE 104.

If the DM-RS sequence assignments to be used for UL CoMP areUE-specific, control plane circuitry 140 may assign both base sequencesand CSs in a UE-specific manner. To support UE-specific configuration ofDM-RS sequences, eNB 108 a may configure a limited number of basesequences at the cell level instead of each cell being associated withonly one base sequence. There may be overlap between the sets of basesequences associated with different points in the CRM set. As a result,eNB 108 a may dynamically assign scheduled UEs, such as UE 104, a basesequence from the set of base sequences for this CRM set. eNB 108 a maydynamically assign the scheduled UEs based on scheduling decisions madeat eNB 108 a.

eNB 108 a may semi-statically, e.g., at the RRC level, configure a superset of base sequences through broadcast or dedicated signaling. Notethat, according to the LTE Rel-10 specifications, the cell-specific basesequences are derived using the physical cell-ID (PCI). The RRCconfiguration of this set of base sequences can also be based on the useof cell-IDs.

According to various embodiments, eNB 108 a may reserve virtual cell-IDs(VCIDs) for the calculation of base sequence seeds used to derive thebase sequences, group hopping patterns, and sequence hopping patterns.Alternatively, eNB 108 a may rely on RRC configurations that directlylist the value of seeds to be used to derive the base sequences, grouphopping, and sequence hopping patterns. According to embodiments, nodynamic indication of DM-RS sequences (described below) would benecessary if eNB 108 a configures a single VCID instead of the super setof VCIDs/base sequence seeds via semi-static RRC signaling.

For dynamic indication of DM-RS sequences, eNB 108 a may use MAC-CEcircuitry 142 to signal the dynamic selection of the seed/VCID to beused by UL CoMP for a given UE. eNB 108 a may combine dynamic selectionof the seed/virtual cell-IDs with MAC-CE messaging used for UL PCsetting. eNB 108 a may use physical layer circuitry 132 to signaldynamic selection of the seed/virtual cell-IDs through Downlink ControlInformation (DCI) carried by the Physical Downlink Control Channel(PDCCH) using an explicit or implicit index, e.g. using some pre-definedorder, to the seed/VCID in the configuration message.

eNB 108 a and UE 104 may be configured to determine a value of CS forthe UL DM-RS. eNB 108 a and UE 104 may derive the CS based on threeparameters: n⁽¹⁾ _(DMRS), n⁽²⁾ _(DMRS,λ), n_(PN)(n_(S)). n⁽¹⁾ _(DMRS) isa CS parameter that is specified by a parameter named cyclicshift(specified according to Table 5.5.2.1.1-2 of 3GPP TS 36.211) which maybe provided by higher layers, such as MAC and RRC, as in LTE Rel-10(non-CoMP) operation. n⁽²⁾ _(DMRS,λ), is a CS parameter that mayindicate the CS and OCC to be used by the UE 104 to generate the DM-RSsequence to be transmitted. eNB 108 a may signal n⁽²⁾ _(DMRS,λ) via themost-recent uplink related DCI for the transport block associated withthe corresponding physical uplink shared channel (PUSCH) transmissionand which can be included in the physical downlink control channel(PDCCH), as is done in Rel-10 (non-CoMP) operation. n_(PN)(n_(s)) is aCS parameter that defines slot-by-slot hopping mechanism between the CSsused by UE 104, and is derived from the physical cell ID according toRel-10 specifications. The application of n_(PN)(n_(s)) may depend onthe same seed/VCID used for the derivation of the base sequence or maybe signaled by the eNB 108 a, independent of the seed/VCID used forderivation of the base sequence. Additionally, to increase the usercapacity of UL DM-RS for UL CoMP, the number of CSs that can be signaledby UE 104 or/and eNB 108 a may be extended from 8 to a higher number,e.g., 12, by using one extra bit in the DCI.

If OCC is employed by eNB 108 a to multiplex UL DM-RS transmissions, theOCC information may be configured in a UE-specific manner via the n⁽²⁾_(DMRS,λ) parameter and may be communicated to the UE dynamicallythrough the DCI carried by the PDCCH, as in Rel-10 (non-CoMP) operation.

IF eNB 108 a employs a UE-specific assignment of SRS base sequences, eNB108 a may be configured to signal the SRS parameters in a manner similarto that described for UE-specific UL DM-RS. In other words, eNB 108 amay signal SRS parameters with a combination of semi-static settings fora limited set of choices using broadcast/unicast RRC signaling followedby UE-specific dynamic setting at the RRC or MAC messaging level.Similar to the case of UE-specific DM-RS, dynamic signaling may notprovide added benefit if only a single choice of SRS base sequence(based on explicit RRC signaling of the seed or VCID) is configuredsemi-statically via RRC. To increase user capacity of SRS for efficientUL CoMP operation, the number of CSs that can be signaled may beextended from 8 to a higher number, e.g., 16, by using one extra bit inthe DCI.

UL PC parameters for SRS transmission may be selected based on the ULCoMP cooperating set and in a similar manner as described earlier forthe signaling of the UL PC parameters (for PUSCH/PUCCH transmission)with the signaling of the CSI-RS resource indices corresponding to theUL CoMP cooperating set. For SRS PC purposes, it may be sufficient tosemi-statically signal, via RRC layer circuitry 126 and 144, only thepreferred CSI-RS resource index for pathloss information to be used bythe UE for open loop power control (OLPC) for SRS.

PUCCH resource allocation parameters may include UE-specific ACK/NACKresource offset (N⁽¹⁾ _(PUCCH)) for dynamic resource indication forPUCCH format 1a/1b, wherein N⁽¹⁾ _(PUCCH) indicates the startinglocation of dynamic ACK/NACK. UE-specific ACK/NACK resource offsetsignaling may reduce potential collisions at the pico-cell during timeswhen UE 104 receives downlink information from a macro-cell, e.g., eNB108 b, while transmitting uplink information to a pico-cell, e.g., eNB108 a. PUCCH resource allocation parameters may include theconfiguration of the UL CoMP cooperation set in a UE-specific way.Further, the eNB 108 a may signal VCID values to generate PUCCH basesequences in a UE-specific way via RRC layer circuitry 144 in order toachieve gains from better interference orthogonalization between PUCCHtransmissions by UEs in neighboring cells within the CoMP set and/orfrom area splitting gains in scenarios wherein a number of low powernodes (LPNs) share the same cell identity with a macro node as in CoMPScenario 4 (as defined in 3GPP TR 36.819). According to variousembodiments, the values for the VCID or base sequence seeds for PUSCHDM-RS, PUCCH, and SRS may be independent.

FIG. 2 illustrates a flow diagram 200 of signaling UE-specific SRSparameters according to embodiments.

At block 202, a UE may receive, through RRC signaling, a plurality ofsets of SRS parameters of a cell to which the UE is connected. Theplurality of sets of SRS parameters may be broadcast or may be unicastby the cell.

At block 204, a UE may receive, through RRC-level signaling or mediaaccess control (MAC)-level signaling, an indication of a set of SRSparameters, selected from the plurality of sets, to be used for SRStransmission. Receipt of the indication of the set of SRS parameters mayenable the UE to operate efficiently by enabling the UE to select from afinite set of parameters in place of causing the UE to determine the SRSparameters based on other information.

According to embodiments, the eNB may be configured to signal more thaneight cyclic shift values to increase capacity of SRS in UL CoMPoperation. The eNB may also be configured to semi-statically determineand signal a preferred one of a number of RPs that may be indicated by acertain CSI-RS index. Semi-statically signaling a preferred RP mayenable the UE to obtain pathloss information that may be used by the UEto determine open loop power control parameters for SRS transmissions.The UE may receive CSI-RS indices from the eNB and may semi-staticallydetermine a respective CSI-RS index of the preferred one of a number ofRPs of an UL CoMP cooperating set based on an RRC message from the eNB.

According to other embodiments, a UE may be enabled or configured toadjust power control parameters of SRS transmissions based on a UL CoMPcooperating set. The UE may adjust the power control parameterscorresponding to a plurality of CSI-RS resource indices signaled by theeNB that may correspond to the UL CoMP cooperating set.

FIG. 3 illustrates a flow diagram 300 of PUCCH resource allocation andPUCCH sequence assignment for efficient support of UL CoMP.

At block 302, a UE may be configured to determine UE-specific ACK/NACKresource offset N⁽¹⁾ _(PUCCH) for transmitting PUCCH with dynamicACK/NACK, e.g., PUCCH formats 1a/1b as specified in 3GPP TS 36.211.

At block 304, a UE may be configured to determine a configuration of anuplink CoMP cooperation set, a base sequence assignment based on anexplicit indication of a virtual cell identification, or an explicitindication of a UE-specific base sequence assignment to support UL CoMPwith better inter-point interference mitigation and/or with areasplitting gains.

FIG. 4 illustrates a flow diagram 400 of signaling UE-specific UL DM-RSparameters according to embodiments.

At block 402, a UE may receive, through semi-static RRC signaling, aplurality of sets of UE-specific DM-RS parameters. The plurality of setsof SRS parameters may be broadcast or may be unicast by the cell.

At block 404, a UE may receive, through media access control (MAC)-levelsignaling or via the latest uplink-related DCI carried by the PDCCH, anindication of a set of DM-RS parameters, selected from the plurality ofsets, to be used for DM-RS transmission. According to embodiments, thedynamic signaling may not provide additional benefit if only a singleset of UE-specific DM-RS parameters is semi-statically signaled at RRClayer.

UE 102 and eNB 104 described herein may be implemented into a systemusing any suitable hardware and/or software to configure as desired.FIG. 5 illustrates, for one embodiment, an example system 500 comprisingone or more processor(s) 504, system control logic 508 coupled with atleast one of the processor(s) 504, system memory 512 coupled with systemcontrol logic 508, non-volatile memory (NVM)/storage 516 coupled withsystem control logic 508, and a network interface 520 coupled withsystem control logic 508.

Processor(s) 504 may include one or more single-core or multi-coreprocessors. Processor(s) 504 may include any combination ofgeneral-purpose processors and dedicated processors (e.g., graphicsprocessors, application processors, baseband processors, etc.). In anembodiment in which the system 500 implements UE 104, processors(s) 504may be included in communication module 112. In an embodiment in whichthe system 500 implements eNB 108, processor(s) 504 may be included incommunications module 128. According to various embodiments,processor(s) 504 and system memory 512 may be configured as user planecircuitry 122, control plane circuitry 124, and/or RRC circuitry 126.According to various embodiments, processor(s) 504 and system memory 512may be configured as user plane circuitry 138, control plane circuitry140, and/or RRC circuitry 144.

System control logic 508 for one embodiment may include any suitableinterface controllers to provide for any suitable interface to at leastone of the processor(s) 504 and/or to any suitable device or componentin communication with system control logic 508.

System control logic 508 for one embodiment may include one or morememory controller(s) to provide an interface to system memory 512.System memory 512 may be used to load and store data and/orinstructions, for example, for system 500. System memory 512 for oneembodiment may include any suitable volatile memory, such as suitabledynamic random access memory (DRAM), for example.

NVM/storage 516 may include one or more tangible, non-transitorycomputer-readable media used to store data and/or instructions, forexample. NVM/storage 516 may include any suitable non-volatile memory,such as flash memory, for example, and/or may include any suitablenon-volatile storage device(s), such as one or more hard disk drive(s)(HDD(s)), one or more compact disk (CD) drive(s), and/or one or moredigital versatile disk (DVD) drive(s), for example.

The NVM/storage 516 may include a storage resource physically part of adevice on which the system 500 is installed or it may be accessible by,but not necessarily a part of, the device. For example, the NVM/storage516 may be accessed over a network via the network interface 520.

System memory 512 and NVM/storage 516 may respectively include, inparticular, temporal and persistent copies of instructions 524.Instructions 524 may include instructions that when executed by at leastone of the processor(s) 504 result in the system 500 implementing a oneof the methods FIGS. 2-4, described herein. In some embodiments,instructions 524, or hardware, firmware, and/or software componentsthereof, may additionally/alternatively be located in the system controllogic 508, the network interface 520, and/or the processor(s) 504.

Network interface 520 may have a transceiver 522 to provide a radiointerface for system 500 to communicate over one or more network(s)and/or with any other suitable device. The transceiver 522 may beimplemented at part of physical layer circuitry 118 or 132. In variousembodiments, the transceiver 522 may be integrated with other componentsof system 500. For example, the transceiver 522 may include a processorof the processor(s) 504, memory of the system memory 512, andNVM/Storage of NVM/Storage 516. Network interface 520 may include anysuitable hardware and/or firmware. Network interface 520 may include aplurality of antennas to provide a multiple input, multiple output radiointerface. Network interface 520 for one embodiment may include, forexample, a network adapter, a wireless network adapter, a telephonemodem, and/or a wireless modem.

For one embodiment, at least one of the processor(s) 504 may be packagedtogether with logic for one or more controller(s) of system controllogic 508. For one embodiment, at least one of the processor(s) 504 maybe packaged together with logic for one or more controllers of systemcontrol logic 508 to form a System in Package (SiP). For one embodiment,at least one of the processor(s) 504 may be integrated on the same diewith logic for one or more controller(s) of system control logic 508.For one embodiment, at least one of the processor(s) 504 may beintegrated on the same die with logic for one or more controller(s) ofsystem control logic 508 to form a System on Chip (SoC).

The system 500 may further include input/output (I/O) devices 532. TheI/O devices 532 may include user interfaces designed to enable userinteraction with the system 500, peripheral component interfacesdesigned to enable peripheral component interaction with the system 500,and/or sensors designed to determine environmental conditions and/orlocation information related to the system 500.

In various embodiments, the user interfaces could include, but are notlimited to, a display (e.g., a liquid crystal display, a touch screendisplay, etc.), a speaker, a microphone, one or more cameras (e.g., astill camera and/or a video camera), a flashlight (e.g., a lightemitting diode flash), and a keyboard.

In various embodiments, the peripheral component interfaces may include,but are not limited to, a non-volatile memory port, an audio jack, and apower supply interface.

In various embodiments, the sensors may include, but are not limited to,a gyro sensor, an accelerometer, a proximity sensor, an ambient lightsensor, and a positioning unit. The positioning unit may also be partof, or interact with, the network interface 520 to communicate withcomponents of a positioning network, e.g., a global positioning system(GPS) satellite.

In various embodiments, the system 500 may be a mobile computing devicesuch as, but not limited to, a laptop computing device, a tabletcomputing device, a netbook, a smartphone, etc. In various embodiments,system 500 may have more or less components, and/or differentarchitectures.

According to various embodiments, an apparatus may include one or morecomputer-readable storage media configured to store a number ofinstructions. The apparatus may include one or more processors coupledto the one or more computer-readable storage media. The one or moreprocessors, in response to executing the number of instructions, may beconfigured to receive channel state information reference signal(CSI-RS) resource configuration information; determine a number ofCSI-RS indices based on the CSI-RS configuration information; andidentify a number of points of an uplink coordinated multi-point (CoMP)cooperating set based on the number of CSI-RS indices. The one or moreprocessors and one or more computer-readable media may be configured ascontrol-plane circuitry of the apparatus. The CSI-RS resourceconfiguration information may be received by radio resource control(RRC) circuitry of the control-plane circuitry as part of a CoMPinitialization process.

In embodiments, the CSI-RS resource configuration information mayinclude transmission parameters associated with CSI-RS. The transmissionparameters may include transmit power, periodicity, subframe offset,initialization seeds, and/or number of utilized antenna ports. Thenumber of CSI-RS indices may be included in the CSI-RS configurationinformation, or the one or more processors may be configured todetermine the number of CSI-RS indices based on an order of CSI-RSsincluded in the CSI-RS resource configuration information.

In embodiments, the one or more processors may be configured to receivea message; determine, based on the message, a CoMP reception point (RP)set that may include a subset of the points of the CoMP cooperating setthat are to receive an uplink data transmission from the apparatus; anddetermine, based on the message, uplink power control parameters. Theone or more processors may be further configured to receive a number ofuplink power control parameter sets that may respectively correspond toa number of CoMP RP sets; and determine the uplink power controlparameters based on the uplink power control parameter set that maycorrespond to the CoMP RP set. The uplink power control parameters maybe included in the message. The uplink power control parameters mayinclude a target signal to noise ratio and a, wherein a may be afractional power control parameter.

In embodiments, the one or more processors may be further configured todetermine pathloss information based on a message fed back from one ormore points of the CoMP cooperating set. The one or more processors maybe further configured to determine the pathloss information based on anaverage received power of the CSI-RS information, as measured by theapparatus. The one or more processors may be further configured tosemi-statically determine the respective CSI-RS index of a preferred oneof the number of points of the uplink CoMP cooperating set received viaan RRC message, wherein the preferred one of the number of points isconfigured to actively receive data from the apparatus. The one or moreprocessors may be further configured to derive a number of basesequences, group hopping patterns, and/or sequence hopping patterns fromone or more virtual cell identifications.

According to embodiments, the one or more processors may be configuredto receive a list of uplink power control parameter sets thatrespectively correspond to receive point sets; determine a receptionpoint set, which is may be subset of the uplink CoMP cooperating set;determine an uplink power control parameter set that may correspond tothe reception point set; and control transmission of uplink signals tothe reception point set based on the uplink power control parameter set.

According to various embodiments, an eNodeB may include one or morecomputer-readable media configured to store a number of instructions;and one or more processors coupled to the one or more computer-readablemedia. In response to executing the number of instructions, the one ormore processors may be configured to support user equipment(UE)-specific configuration of uplink demodulation reference signals(DM-RS). The one or more processors may be configured to configure anumber of base sequences at a cell-level; determine communicationschedules of one or more UEs; and dynamically assign respective basesequences from the number of base sequences to the one or more UEs basedon the determined communication schedules. The number of base sequencesmay be associated with a particular coordinated multipoint (CoMP)resource management (CRM) set. The uplink DM-RS may include parametersthat enable each of the one or more UEs to select one of the number ofbase sequences, cyclic shift (CS) hopping pattern, group hoppingpattern, sequence hopping pattern, a cyclic shift, and an orthogonalcover code (OCC) to determine respective DM-RS sequences that may beassociated with respective ones of the one or more UEs. The number ofbase sequences may be configured semi-statically with radio resourcecontrol (RRC) level broadcast signaling or RRC level dedicatedsignaling.

In embodiments, the one or more processors may be further configured tosignal dynamic selection of one of a number of virtual cellidentifications through a media access control-control element (MAC-CE).The one or more virtual cell identifications may enable derivation ofthe number of base sequences. The one or more processors may beconfigured to combine dynamic selection of the one of the number ofvirtual cell identifications with MAC-CE messaging used to set uplinkpower control parameters. The one or more processors may be configuredto signal dynamic selection of the one of the number of virtual cellidentifications, in downlink control information (DCI) carried by aphysical downlink control channel (PDCCH), with indices assigned to theone or more virtual cell identifications. The one or more processors maybe further configured to signal one of 8 or more cyclic shift valuesassociated with the uplink DM-RS. The one or more processors may beconfigured to signal one of 8 or more cyclic shift values to increasecapacity of SRS in uplink CoMP operation.

In embodiments, the one or more processors may be configured tosemi-statically signal a preferred one of a number of reception pointsindicated by a corresponding one of a number of channel stateinformation resource signals (CSI-RS) indices to obtain pathlossinformation that may be usable by the one or more UEs for open looppower control for SRS transmissions. The one or more processors may beconfigured to adjust power control parameters of SRS transmissions basedon an uplink CoMP cooperating set with signals to a number of CSI-RSresource indices that correspond to the uplink CoMP cooperating set.

According to various embodiments, one or more computer readable mediahaving instructions which, when executed by a processor of a userequipment (UE), may enable the UE to receive, through radio resourcecontrol (RRC) signaling, a number of sets of sounding reference signal(SRS) parameters of a cell to which the UE is connected. Theinstructions may enable the UE to receive, through RRC-level signalingor media access control (MAC)-level signaling, an indication of a set ofSRS parameters, selected from the number of sets, to be used for SRStransmission. The number of sets may be broadcast or unicast by thecell. The instructions may further enable the UE to adjust power controlparameters of SRS transmissions based on an uplink cooperatingmultipoint (CoMP) cooperating set with signals to the number of CSI-RSresource indices that correspond to the uplink CoMP cooperating set.

According to various embodiments, one or more computer-readable mediahaving instructions which, when executed by a processor of an eNodeB,may enable the eNodeB to support coordinated multipoint (CoMP)operations and may enable the eNodeB to determine UE-specificacknowledge (ACK) and negative-acknowledge (NACK) resource offsets N⁽¹⁾_(PUCCH) for dynamic resource allocation of physical uplink controlchannel (PUCCH) carrying dynamic ACK/NACK, and transmit the ACK/NACKresource offset N⁽¹⁾ _(PUCCH) to a respective UE. The instructions mayenable the eNodeB to determine the UE-specific ACK/NACK resource offsetN⁽¹⁾ _(PUCCH) for PUCCH formats 1a and 1b. The PUCCH formats 1a and 1bmay use a physical cell ID. The instructions may enable the eNodeB totransmit a different virtual cell ID index for each PUCCH format used bya UE.

Although certain embodiments have been illustrated and described hereinfor purposes of description, a wide variety of alternate and/orequivalent embodiments or implementations calculated to achieve the samepurposes may be substituted for the embodiments shown and describedwithout departing from the scope of the present disclosure. Thisapplication is intended to cover any adaptations or variations of theembodiments discussed herein. Therefore, it is manifestly intended thatembodiments described herein be limited only by the claims and theequivalents thereof.

What is claimed is:
 1. One or more computer readable media havinginstructions thereon that, in response to execution by one or moreprocessing devices of a user equipment (UE), cause the UE to: determinea physical layer cell identity corresponding to a cell of an evolveduniversal mobile telecommunication system terrestrial radio accessnetwork (E-UTRAN); receive an indicator of a virtual cell identity viaradio resource control signaling, the virtual cell identity differentfrom a physical layer cell identity corresponding to a cell of anevolved universal mobile telecommunication system terrestrial radioaccess network (E-UTRAN); receive a cyclic shift hop initializationvalue different from the virtual cell identity; and generate ademodulation reference signal (DM-RS) parameter based at least in parton the virtual cell identity, and generate a cyclic shift for a DM-RS byinitializing a pseudo-random sequence generator with the cyclic shifthop initialization value.
 2. The one or more computer readable media ofclaim 1, wherein the DM-RS parameter is a group hopping pattern.
 3. Theone or more computer readable media of claim 1, wherein the DM-RSparameter is associated with a physical uplink shared channel.
 4. Theone or more computer readable media of claim 1, wherein the DM-RSparameter is a sequence hopping parameter.
 5. The one or more computerreadable media of claim 1, wherein generate a DM-RS parameter based atleast in part on the virtual cell identity comprises initialize apseudo-random sequence generator with the virtual cell identity.
 6. Theone or more computer readable media of claim 1, wherein the DM-RSparameter is a cyclic shift for a DM-RS for a physical uplink sharedchannel.
 7. The one or more computer readable media of claim 1, whereinthe instructions, in response to execution by the one or more processingdevices, cause the UE to communicate with a positioning network.
 8. Theone or more computer readable media of claim 1, wherein the cyclic shifthop initialization value is received via radio resource controlsignaling.
 9. A method, comprising: selecting, by an eNB, a virtual cellidentity, the virtual cell identity different from a physical layer cellidentity corresponding to a cell of an evolved universal mobiletelecommunication system terrestrial radio access network (E-UTRAN);selecting, by the eNB, a cyclic shift hop initialization value differentfrom the virtual cell identity; providing, by the eNB to a userequipment (UE) via radio resource control signaling, an indicator of thevirtual cell identity for use in generating a demodulation referencesignal (DM-RS) parameter based at least in part on the indicator, and anindicator of the cyclic shift hop initialization value for use ingenerating a cyclic shift for a DM-RS by initializing a pseudo-randomsequence generator with the cyclic shift hop initialization value. 10.The method of claim 9, wherein the DM-RS parameter is a group hoppingpattern.
 11. The method of claim 9, wherein the DM-RS parameter isassociated with a physical uplink shared channel.
 12. The method ofclaim 9, wherein the DM-RS parameter is a sequence hopping parameter.13. The method of claim 9, wherein providing, by the eNB to the UE, theindicator of the virtual cell identity for use in generating a DM-RSparameter based at least in part on the indicator comprises providing,by the eNB to the UE, the indicator for use in initializing apseudo-random sequence generator with the virtual cell identity.
 14. Themethod of claim 9, wherein the DM-RS parameter is a cyclic shift for aDM-RS for a physical uplink shared channel.
 15. The method of claim 9,wherein the indicator of the virtual cell identity is provided to the UEfor use in generating a DM-RS parameter based at least in part on theindicator and for use in generating a sounding reference signal (SRS)parameter based at least in part on the indicator.
 16. The method ofclaim 9, wherein the cyclic shift hop initialization value is providedvia radio resource control signaling.
 17. A user equipment (UE)comprising: means for receiving an indicator of a UE-specificacknowledge and negative-acknowledge (AN) resource offset for a physicaluplink control channel (PUCCH), wherein the AN resource offset isdifferent from a virtual cell identity used by the UE to generate ademodulation reference signal (DM-RS) parameter; and means fordetermining a PUCCH resource based at least in part on the AN resourceoffset.
 18. The UE of claim 17, further comprising: means for causingthe UE to use the determined PUCCH resource for transmission of AN. 19.The UE of claim 17, wherein the indicator of the AN resource offset isreceived via radio resource control signaling.
 20. One or more computerreadable media having instructions thereon that, in response toexecution by one or more processing devices of an eNB, cause the eNB to:select a user equipment (UE)-specific acknowledge andnegative-acknowledge (AN) resource offset for a physical uplink controlchannel (PUCCH), wherein the AN resource offset is different from avirtual cell identity used by the UE to generate a demodulationreference signal (DM-RS) parameter; and provide an indicator of the ANresource offset, to a UE, for use in determining a PUCCH resource basedat least in part on the indicator.
 21. The one or more computer readablemedia of claim 20, wherein the instructions, in response to execution bythe one or more processing devices, cause the eNB to receive ANtransmitted from the UE in the determined PUCCH resource.
 22. The one ormore computer readable media of claim 21, wherein the indicator of theAN resource offset is provided, to the UE, via radio resource controlsignaling.